Flat-brane Compactifications in Supergravity Induced by Scalars

Abstract

We discuss flat compactifications of supergravities in diverse dimensions in the presence of branes. The compactification is induced by the scalar fields of supergravity and it is such that there is no relic cosmological constant on the brane, rendering this way the latter flat. We discuss in particular the D=4, $N=2,4$ and D=8, N=1 supergravities with $n=1,2,3$ vector multiplets where the scalar manifolds are Grassmannian cosets of the form $SO(2,n)/SO(2)\times SO(n)$. By introducing branes at certain points in the transverse space, finite energy solutions to the field equations are constructed. Some of the solutions we present may be interpreted as intersecting branes.